Object-oriented software environments encapsulate functionality and data within software data constructs referred to as objects. Objects are black boxes, in which all interaction therewith is accomplished by calling methods, or procedures, of the objects. The methods of an object are said to be supported by the object, and are particularly defined by object-oriented interfaces. For instance, an object-oriented interface may define the data, if any, that a method of an object receives as input, which is referred to as the arguments of the object-oriented interface, as well as the data, if any, that the method returns as output.
One particular type of object-oriented software environment is the Common Information Model (CIM). The CIM is an object-oriented model for describing management information. It is implementation independent, and allows different management applications to collect data from a variety of different sources. The CIM includes various schemas of objects for systems, networks, applications, and devices, and allows for additional schemas to be added as needed. The CIM can be used in conjunction with the Simple Network Management Protocol (SNMP), in that it provides for the interface of CIM data with SNMP processors for easier network and resource management. The CIM is managed by the Distributed Management Task Force, Inc., and the specification for the CIM is available on the Internet at the web site http://www.dmtf.org/standards/cim/.
Within the CIM, objects may be required by specification to expose, or make available, certain object-oriented interfaces publicly. That is, a given object, to comply with the CIM, may have to have certain methods that are defined by certain object-oriented interfaces, and which are available to be discovered and called by any other object within the CIM. Such object-oriented interfaces are said to be publicly queryable, because any object can learn of the interfaces by querying the objects supporting these interfaces. Such object-oriented interfaces are said to be publicly callable as well, because any object can call the methods defined by the interfaces.
The requirement that certain object-oriented interfaces be publicly queryable and have their methods publicly callable can be disadvantageous, however. Some objects may wish to reserve certain methods as private methods that are callable only by other, inter-related objects. However, because the object-oriented interfaces defining these methods are required to be publicly queryable, any object can learn of them. Furthermore, where the methods are required to be publicly callable, any object can also call these methods to invoke them, which means that access control limiting the invocation of the methods only to inter-related objects cannot be accomplished.